1. Field of Invention
The present invention relates to a supporting frame for a portable light, and more particularly to a worklight stand, which can be quickly and easily unfolded for substantially supporting a worklight thereon and for selectively adjusting a projecting angle of the worklight.
2. Description of Related Arts
Portable worklights are considered as one of the common tools for illumination. Generally, there are two types of worklight, which are floor-type worklight and stand-type worklight, sold commercially. The floor-type worklight is usually placed on a floor through the base of the worklight which typically elevate light housing of the worklight a few inches off of the floor. The stand-type worklight incorporates with a stand to elevate the light housing of the worklight several feet off of the floor.
The stand-type worklight, such as U.S. Pat. No. 6,213,626, would be beneficial and more economical in comparison with the floor-type worklight because the stand-type worklight can function as both the floor-type worklight by detaching the stand from the light housing to function and the stand-type worklight by attaching the stand to the light housing.
However, the stand-type worklight has several drawbacks. As shown in FIG. 1, the stand comprises a supporting pole 1A having an upper end portion detachably attached to the worklight, a collar 2A slidably connected to the supporting pole 1A, and a plurality of legs 3A pivotally connected to the collar 2A to radially extend from the supporting pole 1A, in such a manner that when the collar 2A is downwardly slid along the supporting pole 1A, the legs 3A are radially and outwardly extended so as to support the worklight on the floor. The stand further comprises a plurality of rods 4A each having two ends pivotally connected to a bottom end of the supporting pole 1A and the corresponding leg 3A respectively so as to retain the legs 3A in such unfolded position.
Moreover, the stand further comprises two U-shaped pivot legs 5A each having two ends pivotally connected to the worklight wherein the two pivot legs 5A are adapted to pivotally fold apart to support the worklight on the floor. In addition, the two pivot legs 5A are pivotally folded to overlap with each other wherein the worklight is supported on the supporting pole 1A via the overlapped pivot legs 5A as one-point support configuration such that the weight of the worklight causes the supporting pole 1A to be bent sidewardly such that stresses will be created round the ends of the pivot legs 5A. The stress will then cause a tear at the pivot legs 5A so that the pivot legs 5A will be permanently misshaped at the stress point over a period of continuous use.
Furthermore, since each of the pivot legs 5A has a predetermined fixed height such that the worklight must be rotated about the pivot ends of the pivot legs 5A to adjust the projecting angle. However, the rotational movement of the worklight is restricted by the pivot legs 5A so that the adjustment of the projecting angle of the worklight will be limited. If the worklight is relatively light, such as 10 lbs, the user is able to rotatably elevate the worklight with respect to the pivot legs 5A so as to selectively adjust the projecting angle of the worklight. However, if the worklight is relatively heavy, such as 50 lbs or more, the rotational movement of the worklight for adjusting the projecting angle thereof will cause the unstably support of the worklight on the stand. In other words, it is a hassle for the user to adjust the projecting angle of the worklight once the worklight is supported on the stand.
According to the structural design of the stand, when the worklight is supported on the stand, a downward force of the weight of the worklight is distributed to the legs 3A evenly. However, the weight of the worklight will force the legs 3A to extend outwardly and radially with respect to the supporting pole 1A, so as to drive the collar 2A to slide downwardly along the supporting pole 1A. In order to retain the legs 3A at the unfolded position, each of the rods 4A must be strong enough to overcome the outward radial force of each of the legs 3A for supporting the worklight. It is unreasonable to strengthen the rod 4A to support the weight of the worklight.
In addition, since the structure of each leg 3A must be stronger than that of the respective rod 4A, the weight of the legs 3A will drive the collar 2A to slide downwardly supporting pole 1A once the stand is lifted up. Therefore, the stand must employ a safety locker to lock up the legs 3A at its folded position.
It is worth to mention that when the structural design of the rod 4A is altered, the radial extending movement of each of the legs 3A must be correspondingly changed, which may significantly affect the folding operation of the stand. In other words, the rods 3A play a vital role in the stand to not only support the worklight but also stabilize the worklight with the stand.